In a steady flow, a liquid move between two sections namely Section 1 and Section 2. Data were gathered. For section 1 : Area= 10ft^2 , speed= 100ft/min, specific volume= 4ft^3/lb. For section 2: Area= 2ft^2 , density= 0.2 lb/ft^3. Find the mass flow rate in lb/s.

(1) We are trying to remove tetrachloroethene (C2Cl4) from ground water by air stripping process. The maximum level of tetrachloroethene in the ground water is 5 mg/L and this must be reduced to 50µg/L using air stripping column. Here is given information; Liquid-phase mass transfer (m/sec) kL =19.86 x10-4 m/sec Wetted packing area (m2/m3 ), aw = 89.18 m2/m3 gas-phase mass transfer (m/sec), kG =4.94 x10-3 m/sec liquid flow rate, Qw = 8L/sec Temperature = 6ºC Column diameter = 3.0 ft Air -to-water ratio (QA/QW) = 40 (You need Appendix A for calculation of H) a) Determine liquid loading rate, L b) Stripping factor c) Height of transfer unit, HTU d) Number of transfer unit, NTU e) Height of packing in column, Z

(2) A tank containing 10,000 gallons of trichloroethane ruptures contaminating 3,000 ft2 of soil. Diffusion coefficient of 0.80cm2/sec. Trichloroethane saturation in air =500g/m3 Humidity = 0.4 Temperature = 20ºC Thickness of stagnant boundary layer = 0.5cm Specific gravity of Trichloroethane =1.321 i) Use Hartley’s method to estimate the rate of volatilization of trichloroethane Ii) Calculate the time required for the entire 10,000 gallons to evaporate.

Using a 2.1 mm x 50 mm C18 column and a flow rate of 300 uL/min the attached chromatograms were obtained using a time of flight mass spectrometer as a detector (Note the mass spectrometer data are not required to answer these questions). These 3 samples provide approximately 30 peaks (this is a high estimate) in ~3 minutes. Using these 3 chromatograms, answer the following questions about this chromatographic system: Define bed volume and determine this value for the column used across these 3 samples. Report your answer as an average value and include its standard deviation.

Using an intensity threshold of 50000 counts, and peak elution time window of +/- 0.02 minutes, integrate all peaks across the different spectra and report the area for all identified peaks. Be sure to include a brief description of the approach/method of peak integration. This should include the program/algorithm and settings used. To be clear, your answer should include a printed data sheet (e.g. Excel or Google Sheets) for each chromatogram that lists the peak location, area, and height.

• What is the average peak capacity for the separations (hint: you will need to calculate the number of theoretical plates)?

• If Chromatogram #3 represents an external standard with a concentration of 10 ng at an elution time of 2.73 min (+/- 0.02 min) what are the respective concentrations of the analyte in Chromatograms #1 and #2 assuming the same nominal retention time.?